Power regenerator or filter for DAC?

I have had very good results using isolation transformers with digital gear--transports, DACs and players. Power cord upgrades have been very effective as well, on all but one DAC, the Cambridge IsoMagic. That one had an external PS block to which the AC cord connected, and a better AC cord made no difference to it.

I've also gotten away from the power conditioners and regenerators and gone to the industrial Isolation Transformers. I can't see going back at this point.